Applicators for application of a substance onto a material are well known in the art. For instance, U.S. Pat. No. 5,145,689 discloses an applicator applying adhesive from slotted nozzles in which air is directed toward the medium that leads to swirling of the emerging adhesive threads. This prevents adhesive threads from tearing off and also prevents the formation of drops which could lead to a non-uniform application of adhesive. However, due to the needed supply of air, the applicator becomes complicated and expensive. Such an applicator finds frequent application where widths of material have to be laminated onto a substrate. To minimize the specific consumption of liquid medium and, at the same time, to ensure as uniform a distribution of the medium as possible, the medium is applied intermittently to achieve a grid-like application pattern. In order to enable, at the same time, a high transport speed of the width of material, the medium has to be applied in the direction of movement of the width of material at a high frequency. The grid points extend transversely to the direction of movement of the width of material and are arranged as closely as possible to one another.
In another example, EP 0 474155 A2 and EP 0 367985 A2 illustrate applicators where hole type nozzles are controlled by a pneumatically operated nozzle needle. However, the medium cannot be applied economically to the width of material when it moves at a high speed due to limited maximum cycle frequency of the nozzle units. This limitation is the result of the mass inertia of the nozzle needles and of the control elements.
In yet another example, U.S. Pat. No. 6,464,785 discloses an applicator which has a cylinder control slide that is rotatably operable to provide intermittent or continuous strands of a substance onto a web. However, this design is limited in its ability to quickly shutter the flow of said substance and to provide non-linear strand patterns.
What is needed is an applicator for application of a substance onto a material, wherein the applicator is able to quickly shutter the flow of said substance and is able to provide custom (e.g., non-linear) strand patterns.